ABSTRACT
The goal of the present study was to compare pulmonary function test (PFT) and cardiopulmonary exercise test (CPET) performance in COVID-19 survivors with a control group (CG). This was a cross-sectional study. Patients diagnosed with COVID-19, without severe signs and symptoms, were evaluated one month after the infection. Healthy volunteers matched for sex and age constituted the control group. All volunteers underwent the following assessments: i) clinical evaluation, ii) PTF; and iii) CPET on a cycle ergometer. Metabolic variables were measured by the CareFusion Oxycon Mobile device. In addition, heart rate responses, peak systolic and diastolic blood pressure, and perceived exertion were recorded. Twenty-nine patients with COVID-19 and 18 healthy control subjects were evaluated. Surviving patients of COVID-19 had a mean age of 40 years and had higher body mass index and persistent symptoms compared to the CG (P<0.05), but patients with COVID-19 had more comorbidities, number of medications, and greater impairment of lung function (P<0.05). Regarding CPET, patients surviving COVID-19 had reduced peak workload, oxygen uptake (V̇O2), carbon dioxide output (V̇CO2), circulatory power (CP), and end-tidal pressure for carbon dioxide (PETCO2) (P<0.05). Additionally, survivors had depressed chronotropic and ventilatory responses, low peak oxygen saturation, and greater muscle fatigue (P<0.05) compared to CG. Despite not showing signs and symptoms of severe disease during infection, adult survivors had losses of lung function and cardiorespiratory capacity one month after recovery from COVID-19. In addition, cardiovascular, ventilatory, and lower limb fatigue responses were the main exercise limitations.
ABSTRACT
Obesity is a chronic disease with a multifaceted treatment approach that includes nutritional counseling, structured exercise training, and increased daily physical activity. Increased body mass elicits higher cardiovascular, ventilatory and metabolic demands to varying degrees during exercise. With functional capacity assessment, this variability can be evaluated so individualized guidance for exercise training and daily physical activity can be provided. The aim of the present study was to compare cardiovascular, ventilatory and metabolic responses obtained during a symptom-limited cardiopulmonary exercise test (CPX) on a treadmill to responses obtained by the incremental shuttle walk test (ISWT) in obese women and to propose a peak oxygen consumption (VO2) prediction equation through variables obtained during the ISWT. Forty obese women (BMI ≥30 kg/m2) performed one treadmill CPX and two ISWTs. Heart rate (HR), arterial blood pressure (ABP) and perceived exertion by the Borg scale were measured at rest, during each stage of the exercise protocol, and throughout the recovery period. The predicted maximal heart rate (HRmax) was calculated (210 – age in years) (16) and compared to the HR response during the CPX. Peak VO2 obtained during CPX correlated significantly (P<0.05) with ISWT peak VO2 (r=0.79) as well as ISWT distance (r=0.65). The predictive model for CPX peak VO2, using age and ISWT distance explained 67% of the variability. The current study indicates the ISWT may be used to predict aerobic capacity in obese women when CPX is not a viable option.